Avoid many unnecessary allocations, so so that paint engines attached to pixmaps

do not consume excessive amounts of memory, and so can still be reasonably kept
cached with the pixmap.
Saves 8K for every pixmaps drawn to on raster paint engine. Saves about 2K for other graphicssystems.

Task-number: QTBUG-10215
Reviewed-by: Gunnar

6 files changed, 19 insertions, 7 deletions

diff --git a/src/opengl/gl2paintengineex/qgl2pexvertexarray_p.h b/src/opengl/gl2paintengineex/qgl2pexvertexarray_p.h
index adc69ee..46029b9 100644
--- a/src/opengl/gl2paintengineex/qgl2pexvertexarray_p.h
+++ b/src/opengl/gl2paintengineex/qgl2pexvertexarray_p.h
@@ -100,8 +100,10 @@ class QGL2PEXVertexArray
 {
 public:
     QGL2PEXVertexArray() :
+        vertexArray(0), vertexArrayStops(0),
         maxX(-2e10), maxY(-2e10), minX(2e10), minY(2e10),
-        boundingRectDirty(true) {}
+        boundingRectDirty(true)
+    { }
     
     inline void addRect(const QRectF &rect)
     {
diff --git a/src/opengl/gl2paintengineex/qpaintengineex_opengl2_p.h b/src/opengl/gl2paintengineex/qpaintengineex_opengl2_p.h
index 6ba0c42..0a046dc 100644
--- a/src/opengl/gl2paintengineex/qpaintengineex_opengl2_p.h
+++ b/src/opengl/gl2paintengineex/qpaintengineex_opengl2_p.h
@@ -177,6 +177,7 @@ public:
             ctx(0),
             useSystemClip(true),
             elementIndicesVBOId(0),
+            opacityArray(0),
             snapToPixelGrid(false),
             addOffset(false),
             nativePaintingActive(false),
diff --git a/src/opengl/gl2paintengineex/qtriangulatingstroker.cpp b/src/opengl/gl2paintengineex/qtriangulatingstroker.cpp
index f677ce1..9bc099d 100644
--- a/src/opengl/gl2paintengineex/qtriangulatingstroker.cpp
+++ b/src/opengl/gl2paintengineex/qtriangulatingstroker.cpp
@@ -481,7 +481,8 @@ static void qdashprocessor_cubicTo(qreal, qreal, qreal, qreal, qreal, qreal, voi
 }
 
 QDashedStrokeProcessor::QDashedStrokeProcessor()
-    : m_dash_stroker(0), m_inv_scale(1)
+    : m_points(0), m_types(0),
+      m_dash_stroker(0), m_inv_scale(1)
 {
     m_dash_stroker.setMoveToHook(qdashprocessor_moveTo);
     m_dash_stroker.setLineToHook(qdashprocessor_lineTo);
@@ -499,6 +500,8 @@ void QDashedStrokeProcessor::process(const QVectorPath &path, const QPen &pen, c
 
     m_points.reset();
     m_types.reset();
+    m_points.reserve(path.elementCount());
+    m_types.reserve(path.elementCount());
 
     qreal width = qpen_widthf(pen);
     if (width == 0)
diff --git a/src/opengl/gl2paintengineex/qtriangulatingstroker_p.h b/src/opengl/gl2paintengineex/qtriangulatingstroker_p.h
index 956d7cc..ab27ed6 100644
--- a/src/opengl/gl2paintengineex/qtriangulatingstroker_p.h
+++ b/src/opengl/gl2paintengineex/qtriangulatingstroker_p.h
@@ -54,6 +54,7 @@ QT_BEGIN_NAMESPACE
 class QTriangulatingStroker
 {
 public:
+    QTriangulatingStroker() : m_vertices(0) {}
     void process(const QVectorPath &path, const QPen &pen, const QRectF &clip);
 
     inline int vertexCount() const { return m_vertices.size(); }
diff --git a/src/opengl/gl2paintengineex/qtriangulator.cpp b/src/opengl/gl2paintengineex/qtriangulator.cpp
index ce917ff..df7cbc2 100644
--- a/src/opengl/gl2paintengineex/qtriangulator.cpp
+++ b/src/opengl/gl2paintengineex/qtriangulator.cpp
@@ -510,6 +510,7 @@ template <class T>
 class QMaxHeap
 {
 public:
+    QMaxHeap() : m_data(0) {}
     inline int size() const {return m_data.size();}
     inline bool empty() const {return m_data.isEmpty();}
     inline bool isEmpty() const {return m_data.isEmpty();}
@@ -1299,7 +1300,8 @@ public:
     class ComplexToSimple
     {
     public:
-        inline ComplexToSimple(QTriangulator *parent) : m_parent(parent) { }
+        inline ComplexToSimple(QTriangulator *parent) : m_parent(parent),
+            m_edges(0), m_events(0), m_splits(0) { }
         void decompose();
     private:
         struct Edge
@@ -1412,7 +1414,7 @@ public:
     class SimpleToMonotone
     {
     public:
-        inline SimpleToMonotone(QTriangulator *parent) : m_parent(parent) { }
+        inline SimpleToMonotone(QTriangulator *parent) : m_parent(parent), m_edges(0), m_upperVertex(0) { }
         void decompose();
     private:
         enum VertexType {MergeVertex, EndVertex, RegularVertex, StartVertex, SplitVertex};
@@ -1486,7 +1488,7 @@ public:
         int m_length;
     };
 
-    inline QTriangulator() { }
+    inline QTriangulator() : m_vertices(0) { }
 
     // Call this only once.
     void initialize(const qreal *polygon, int count, uint hint, const QTransform &matrix);
@@ -2709,7 +2711,7 @@ void QTriangulator::SimpleToMonotone::monotoneDecomposition()
         return;
 
     Q_ASSERT(!m_edgeList.root);
-    QDataBuffer<QPair<int, int> > diagonals;
+    QDataBuffer<QPair<int, int> > diagonals(m_upperVertex.size());
 
     int i = 0;
     for (int index = 1; index < m_edges.size(); ++index) {
@@ -2853,7 +2855,7 @@ bool QTriangulator::SimpleToMonotone::CompareVertices::operator () (int i, int j
 void QTriangulator::MonotoneToTriangles::decompose()
 {
     QVector<quint32> result;
-    QDataBuffer<int> stack;
+    QDataBuffer<int> stack(m_parent->m_indices.size());
     m_first = 0;
     // Require at least three more indices.
     while (m_first + 3 <= m_parent->m_indices.size()) {
diff --git a/src/opengl/qpaintengine_opengl.cpp b/src/opengl/qpaintengine_opengl.cpp
index 306fd8b..d2b0d4f 100644
--- a/src/opengl/qpaintengine_opengl.cpp
+++ b/src/opengl/qpaintengine_opengl.cpp
@@ -668,6 +668,7 @@ public:
         , last_created_state(0)
         , shader_ctx(0)
         , grad_palette(0)
+        , tess_points(0)
         , drawable_texture(0)
         , ref_cleaner(this)
         {}
@@ -1950,6 +1951,8 @@ void QOpenGLPaintEnginePrivate::pathToVertexArrays(const QPainterPath &path)
 
 void QOpenGLPaintEnginePrivate::drawVertexArrays()
 {
+    if (tess_points_stops.count() == 0)
+        return;
     glEnableClientState(GL_VERTEX_ARRAY);
     glVertexPointer(2, GL_DOUBLE, 0, tess_points.data());
     int previous_stop = 0;